This invention relates to semiconductor integrated circuit structures. More particularly, it is concerned with substrates for the fabrication of semiconductor integrated circuit devices therein and the methods of producing such substrates.
Monolithic integrated circuit structures containing complementary metal-oxide-silicon (CMOS) devices are well-known. Typically, a complementary pair of devices are fabricated in adjacent sections of opposite conductivity type within a body of silicon. Metal interconnections between the gates and the source/drain regions of the devices and to other circuit components are formed on the surface of the body overlying a nonconductive coating.
In integrated circuit structures of this type each section of the silicon body which contains the active regions of a CMOS device must be electrically isolated so as to prevent interaction with other regions of the body. In addition, it is desirable to reduce the capacitive effects caused by conductive interconnections overlying relatively low resistivity silicon and separated therefrom by intermediate insulating material.